Why does Android have a Root requirement?

A top Android developer has questioned why Android the huge security hole which is the root requirement. Steve Kondik wrote that Android 4.3 introduces some new and much needed security features which not only restrict setuid binaries on the system partition (su), but also limit the capabilities of processes.

In the current architecture, even if you could get elevated privileges, you can't do anything out of the ordinary. Root in the shell via ADB is all I use, and it still works just fine, he said. He said he had no problems as when there is a situation that I'd need root, I just modify the system to accommodate what I'm trying to accomplish in a secure way.

Kondik understood the desire to have full root on stock ROMs, but he said that things had reached a point where it was better to consider better options than root based systems.

“Going forward, I'm interested in building framework extensions and APIs into CM to continue to abolish the root requirement, he said

The only real need to use root requirements include firewalls and network software, potentially requiring raw sockets, managing the DNS resolver and tweaking various sysfs nodes to control the kernel. Since all these can be done without exposing root, and they can be done in a very secure way why bother?